DRILL ASSEMBLY WITH CUTTING PLATES Russian patent published in 2015 - IPC B23B51/00 

FIELD: technological processes.

SUBSTANCE: invention relates to material processing by cutting, a cutting drill assembly with the mechanical attachment of many-sided cutting plates. The drill includes a housing, a central cutting plate installed near the rotation axis and a peripheral cutting plate identical to the central cutting plate. The peripheral cutting plate is installed farther from the rotation axis than the central cutting plate. In order to achieve serviceability, reduce cutting forces and enlarge technological capabilities of the drill, the rotation trajectory of the central cutting plate and the peripheral cutting plate are at least partially overlapped with the formation of an overlapping section; with that, the cutting edge of the internal cutting plate and the cutting edge of the external cutting plate are inclined to the rotation axis in the direction to the part, which provides step-by-step drilling into the processed part. In order to improve the reliability of attachment of the many-sided cutting plates, the central and peripheral cutting plates are made based on an equilateral triangle, with the main and auxiliary cutting edges formed by the intersection of the front surface with the side surfaces. In drill assemblies of such design, the deformation of the cutting plates at tightening of a screw is excluded; fulfilment of the force closure rule is provided, i.e. the direction of the cutting force coincides with the direction of attachment force.

EFFECT: improvement of the serviceability, reduction of cutting forces and enlargement of technological capabilities of the drill.

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